System and method for improved spectrum use

ABSTRACT

A method for improving the use of a transmission spectrum in a multi-sector wireless communication system includes generating a first signal, processing a first signal with a first Auto Tune Combiner, transmitting the first signal on an antenna associated with a first sector, sampling the first signal with a radio frequency test device, generating a second signal, processing the second signal with a second Auto Tune Combiner, transmitting the second signal on an antenna associated with a second sector, and sampling the second signal with the radio frequency test device.

BACKGROUND OF THE INVENTION

The present invention relates to a method and apparatus for thetransmission of communications signals in a wireless network. Moreparticularly, the present invention relates to a method and apparatusfor enhancing spectrum utilization at a wireless communicationstransmission site.

In a wireless communications system, a wireless carrier is often limitedin the amount of radio frequency spectrum it can use in the operation ofthe site. For example, in an e-band license, a wireless carrier may onlybe allotted 5 MHz of spectrum to use for transmitting wireless signals.This 5 MHz of spectrum must be divided into channels on which wirelesssignals are transmitted. In a typical configuration, 30 kHz channels areused, which means that a 5 MHz spectrum may be divided intoapproximately 166 different channels. In this manner, a wirelesscarrier, at a particular wireless communications site, is limited tothese 166 different channels.

Further limitations on the use of these 166 different channels areimposed by the equipment used in a wireless communications site.Depending on the type of equipment used, not all of the 166 channels maybe available for transmission at a particular time. The inability to usemost of the 166 channels creates difficulty in the operation of thewireless communications system.

If the full 5 MHz of spectrum cannot be utilized, then additionalwireless communications sites may need to be constructed. Theconstruction of a wireless communications site involves considerabletime and expense. A typical site, such as a cellular site, involves theconstruction of a tower and an accompanying building to house theelectronic equipment necessary to operate the site. Land must bepurchased, zoning regulations must be complied with, funds forconstruction must be outlaid, and time must be invested in constructingthe site. Therefore, it is desirable to avoid constructing additionalsites by fully utilizing the available spectrum allotted to a wirelesscarrier.

FIG. 1 illustrates a conventional configuration of a wirelesscommunications site. This site 100, which is typically a cellular site,generally includes a set of radio frequency sources 105, a set of AutoTune Combiners 110, a band pass filter 115, a multicoupler unit 120, anantenna 125, a radio frequency test loop device 130, and a multicoupler135. All of these components except the antenna 125, are typicallyhoused in a small building at the wireless communications site. Theantenna 125 is typically mounted to a tower which is also at the site.

In the typical configuration of FIG. 1, the set of radio frequencysources 105 are interconnected to the set of Auto Tune Combiners 110.The set of Auto Tune Combiners 110 is then connected to band pass filter115 which is then connected to multicoupler unit 120. Multicoupler unit120 is interconnected to antenna 125 and radio frequency test loopdevice 130. Radio frequency test loop device 130 is connected tomulticoupler 135, which is then connected to radio source 105.

Typically, the set of radio frequency sources 105 comprises multipleradios—in this case, six 30 watt radios. Each of these 30 watt radios istypically housed in a cabinet contained within a small building adjacentto the tower at the wireless communications site. Each of these 30 wattradios generates a signal at a particular frequency or on a particularchannel that is later transmitted on antenna 125. In this configurationof six radios, the transmission on antenna 125 is limited to sixdifferent frequencies or six different channels. Generally, the numberof radios is limited only by the spectrum that is assigned to a wirelesscarrier as well as the space available in the cabinet and small buildingat the wireless communications site. In other typical configurations,more than six radios are employed at a given site.

The signal generated by each of the six radios then passes to one of theAuto Tune Combiners 110. In the typical configuration, each individualradio has associated with it a single Auto Tune Combiner. In this case,the set of Auto Tune Combiners 110 comprises six separate Auto TuneCombiners that are cabled together. Usually, these six different AutoTune Combiners are all interconnected to an Auto Tune CombinerController (not shown), which controls the operation of the sixindividual Auto Tune Combiners. An Auto Tune Combiner functions tocombine all of the different signals produced by the radios to getmaximum power out to the antenna. In this case, the six 30 watt radiosproduce six signals at six different frequencies. The Auto Tune Combinertakes these six signals at the six different frequencies and combinesthem so as to form one signal that is transmitted by antenna 125.

After the Auto Tune Combiners 110 process the signals from the sixradios 105, the resulting output is passed through band pass filter 115.Band pass filter 115, in a typical configuration, operates to ensurethat the transmission on antenna 125 is within a prespecified frequencyrange. In this case, a wireless provider with 5 MHz of spectrumavailable would configure band pass filter 115 so that any signaltransmitted on antenna 125 would be within the 5 MHz spectrum.

After the signal is filtered by band pass filter 115, it passes tomulticoupler unit 120. Multicoupler unit 120 serves typically as aconnection point for antenna 125 as well as a sampling point for radiofrequency test loop device 130. A coaxial cable typically connectsmulticoupler 120 to antenna 125. It is across this cable that the signalis sent to antenna 125 for transmission. In addition, multicoupler unit120 has two test points, a forward signal test point and a reflectedsignal test point. The forward signal test point of multicoupler unit120 is connected to the forward port of radio frequency test loop device130 and the reflected signal test point on multicoupler unit 120 isconnected to the reflected port of radio frequency test loop device 130.

Radio frequency test loop device 130 (RFTL) samples the forward andreflected signals from multicoupler unit 120. The forward signal path isthe path taken by the signal that is transmitted on antenna 125. Thereflected path is the signal or power reflected back from antenna 125.RFTL 130 takes measurements of the forward path signal and the reflectedpath signal to verify that the six radios are each transmitting at aproper power. The RFTL 130 verifies the power of each frequency andsends signals to the radios to increase or decrease power. Additionally,RFTL 130 verifies that the antenna is operating properly. A controlsignal is sent by RFTL 130 through multicoupler 135 to each of the sixradios contained in radio frequency source 105.

In sum, each of the six radios comprising radio frequency source 105produces six different signals on six different frequencies. These sixdifferent signals are sent to six different Auto Tune Combiners that arecabled together to form Auto Tune Combiner 110. The Auto Tune Combinerscombine the six different signals so as to allow maximum powertransmission on antenna 125. The resulting signal is then filteredthrough band pass filter 115 and sent to antenna 125 throughmulticoupler unit 120. RFTL 130 samples the forward and reflected pathsof the resulting signal from the forward and reflected connections onmulticoupler unit 120. RFTL 130 then performs measurements on theforward and reflected paths to determine whether or not the radios areoperating at the proper power as well as whether the antenna itself isoperating properly. RFTL 130 then sends a feedback signal throughmulticoupler 135 to each of the six radios comprising radio frequencysource 105.

The typical configuration described with reference to FIG. 1 may beimplemented with an Ericsson RBS 884 system. This system typically comesin two different frequency bands, 1900 MHz and 850 MHz. Each of thecomponents of the Ericsson RBS 884 system have certain limitations whichconstrain the number of channels that can be used in a given frequencyspectrum.

The Auto Tune Combiners of this system are specified by Ericsson torequire a 21 channel separation. In this case, channels are 30 kHz apartso that a 21 channel separation requires 630 kHz of spectrum. In theexample of FIG. 1, this means that each of the six different radioscontained in radio frequency source 105 must generate radio signals withfrequencies that are at least 630 kHz apart. In a 5 MHz spectrum, thismeans that at most eight radios may transmit signals on antenna 125 atthe same time.

This limitation is illustrated more clearly in FIG. 2A, which is a tabledepicting the 166 available channels in a 500 MHz spectrum divided into21 different sets. To honor the 21 channel separation specified byEricsson, the radio frequency source 105 which comprises multiple radiosmay only operate on one set of the channel sets depicted in FIG. 2A. Ascan be seen, the channel sets each contain channels that are separatedby 630 kHz or 21 channels. In the typical configuration of FIG. 1, themultiple radios of radio frequency source 105 would be able to use, forexample, channel set 2 which comprises channels 2, 23, 44, 65,86,107,128 and 149. The multiple radios of radio frequency source 105would not be able to use any of the other channels depicted in the tableof FIG. 2A because each of these other channels is closer than 21channels to the given channel set. Practically, this means that out of apossible 5 MHz spectrum comprising 166 30 kHz channels, only eightdifferent channels can be used at the same time. This greatly limits theamount of capacity at a particular wireless communications site.

Through experimentation, the inventors have found that the Auto TuneCombiners of the Ericsson RBS 884 system, without any additionalmanipulation, can operate with an 11 channel separation. In this case,the signals generated by the radios of radio frequency source 105 mustbe at least 11 channels or 330 kHz apart. This greatly increases thenumber of frequencies that can be used at the same time by wirelesstransmission system 100. For example, each of the six different radiosof radio frequency source 105 will be able to use six different channelsthat are 11 channels or 330 kHz apart simultaneously. FIG. 2B depictschannel sets that are 11 channels apart. In FIG. 2B, the entire 166channels of a 5 MHz spectrum are divided into 11 different sets. Each ofthese 11 different sets contains channels that are 11 channels or 330kHz apart. As can be seen, each of these sets contains at least sixchannels. Therefore, each of the six radios of radio frequency source105 can operate simultaneously on the six different channels of a givenset of FIG. 2B. Even with this 11 channel limitation, however, as can beseen in FIG. 2B, only 15 out of a possible 166 channels can be utilizedat the same time. This greatly limits the amount of capacity that can behandled by a given wireless communications site.

A further limitation imposed by the Ericsson RBS 884 is found in RFTL130. RFTL 130 requires four channel separation. This means that theradio frequency signals that are transmitted on antenna 125 and sampledby RFTL 130 must be four channels 120 kHz apart. In the typicalconfiguration of FIG. 1, however, the 11 channel separation of the AutoTune Combiner 110 takes precedence over the four channel separation ofRFTL 130. In other words, the 11 channel separation associated with AutoTune Combiner 110 must be respected, which would also respect the fourchannel separation of RFTL 130. In sum, the typical configuration ofFIG. 1 requires an 11 channel separation which greatly reduces theamount of a given spectrum that can be utilized.

Applicants have recognized the disadvantage of the limitations imposedby the typical configuration of FIG. 1 and have discovered a method andapparatus to overcome these limitations.

SUMMARY OF THE INVENTION

In an aspect consistent with the general principles of the presentinvention, a method for improving the use of a transmission spectrum ina multi-sector wireless communication system includes generating a firstsignal, processing a first signal with a first Auto Tune Combiner,transmitting the first signal on an antenna associated with a firstsector, sampling the first signal with a radio frequency test device,generating a second signal, processing the second signal with a secondAuto Tune Combiner, transmitting the second signal on an antennaassociated with a second sector, and sampling the second signal with theradio frequency test device.

In another aspect of the present invention, an apparatus for improvingthe use of a transmission spectrum in a wireless communication systemincludes a first radio source for generating a first signal, a firstAuto Tune Combiner for processing the first signal, a first antennaassociated with a first sector for transmitting the first signal, asecond radio source for generating a second signal, a second Auto TuneCombiner for processing the second signal, a second antenna associatedwith a second sector for transmitting the second signal, and a radiofrequency test device for sampling the first and second signals.

Additional objects and advantages of the invention will be set forth inpart in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention will be realized and attained bymeans of the elements and combinations particularly pointed out in theappended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of theinvention and together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a block diagram of a wireless communications systemimplemented in the prior art.

FIGS. 2A, 2B, and 2C depict channel sets utilized in conjunction withthe prior art, as well as in conjunction with the present invention.

FIG. 3 is general layout diagram of the antennas in a three sectorwireless communications system.

FIG. 4 is a block diagram of a wireless communications system consistentwith the principles of the present invention.

FIG. 5 is a block diagram of a wireless communications system consistentwith the principles of the present invention.

FIG. 6 is a flow chart depicting the operation of a wirelesscommunications system consistent with the principles of the presentinvention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

The configuration of the components in the exemplary embodiments of thepresent invention allows a wireless communications system to overcomethe limitations noted in the background section. As previouslydescribed, the Auto Tune Combiners of the Ericsson RBS884 system have an11-channel separation limitation, and the radio frequency transmit loopdevices have a 4-channel separation limitation. The configuration of thepresent invention, however, allows transmission on adjacent channels inthe same sector by splitting the transmit paths and sharing RFTL devicesamong radios transmitting on different sectors. By associating radiosthat transmit on the same sector with different Auto Tune Combiners anddifferent RFTL cards, the signals generated by these radios can resideon adjacent channels. Therefore, a tighter use of spectrum can beachieved in a given sector.

Consistent with the general principles of the present invention, anapparatus for improving the use of a transmission spectrum in a wirelesscommunications system includes a first set of radio sources forgenerating a first set of signals, a first set of components forprocessing the first set of signals for transmission, a first antennaassociated with a first sector for transmitting the first set ofsignals, a second set of radio sources for generating the second set ofsignals, a second set of components for processing the second set ofsignals for transmission, a second antenna associated with a secondsector for transmitting a second set of signals, and a sampling devicefor sampling the transmitted first and second sets of signals.

As herein embodied and illustrated in FIG. 4, an apparatus for improvingthe use of a transmission spectrum in a multi-sector wirelesscommunications system may include a first radio 405, a first Auto TuneCombiner (ATC1) 408, a first band pass filter 411, a first multi-couplerunit (MCU1) 414, a first antenna associated with a first sector (AntennaA1) 365, a first radio frequency test loop device (RFTL1) 417, a firstmulti-coupler 420, a second radio 423, a second Auto Tune Combiner(ATC2) 426, a second band pass filter 429, a second multicoupler unit(MCU2) 432, and a second antenna associated with a second sector(Antenna B2) 380. Further, the exemplary apparatus depicted in FIG. 4may include a third radio 440, a third Auto Tune Combiner (ATC3) 443, athird band pass filter 446, a third multi-coupler unit (MCU3) 449, afirst antenna associated with a second sector (Antenna B1) 375, a secondradio frequency test loop device (RFTL2) 452, a second multi-coupler455, a fourth radio 458, a fourth Auto Tune Combiner (ATC4) 461, afourth band pass filter 464, a fourth multi-coupler unit (MCU4) 467, anda second antenna associated with a first sector (Antenna A2) 370.

The configuration of the components of the exemplary embodiment depictedin FIG. 4 is better understood with reference to FIG. 3A. FIG. 3Adepicts a two sector wireless communications system. In FIG. 3A, thetransmission area is divided into two sectors, Sector A 355 and Sector B360. At the center of the transmission area is tower 385. Two sets ofantennas are mounted on tower 385. The first set of antennas, Antenna A1365 and Antenna A2 370 transmit in Sector A 355. The second set ofantennas, Antenna B1 375 and Antenna B2 380, transmit in Sector B 360.The antennas depicted in the apparatus of FIG. 4, in this example,correspond to the antennas depicted in FIG. 3A. In this manner, firstradio 405 and fourth radio 458 transmit in Sector A on Antenna A1 365and Antenna A2 370, respectively. Likewise, the second radio 423 and thethird radio 440 transmit in Sector B on Antenna B2 380 and Antenna B1375, respectively.

Referring again to FIG. 4, first radio 405 generates a first signalwhich is transmitted to ATC1 408 for processing. After ATC1 408processes the first signal, it then proceeds to first band pass filter411 for filtering. After filtering, the signal passes to MCU1 414 towhich Antenna A1 365 is connected. The signal is then broadcast inSector A on Antenna Al 365. RFTL1 417 samples a forward signal and areflected signal from MCU1 414. RFTL1 417 after performing tests on thesampled signals, submits a feedback signal to first multi-coupler 420.The feedback signal then passes from first multi-coupler 420 to firstradio 405. The connections between first radio 405, ATC1 408, first bandpass filter 411, MCU1 414, Antenna A1 365, RFTL1 417, firstmulti-coupler 420, and first radio 405 are typically implemented withcables, such as coaxial cables. In other aspects of the invention, theinterconnection between these devices can be achieved in any convenientmanner. As is known in the prior art, the interconnection between thesedevices can be implemented with cables or by wireless means. Likewise,the interconnections between the remaining components of FIG. 4 may alsobe via cable or via a wireless device.

In the embodiment of FIG. 4, second radio 423 is interconnected to ACT2426. ATC2 426 is connected to second band pass filter 429. Second bandpass filter 429 is connected to MCU2 432. RFTL1 417, as well as AntennaB2 380, are connected to MCU2 432. RFTL1 417 is connected to firstmulti-coupler 420. First multi-coupler 420 is then connected to bothfirst radio 405 and second radio 423.

Likewise, third radio 440 is connected to ATC3 443. ATC3 443 isconnected to third band pass filter 446. Third band pass filter 446 isconnected to MCU3 449. RFTL2 452, as well as Antenna B1 375, areconnected to MCU3 449. RFTL2 452 is connected to second multi-coupler455. Second multi-coupler 455 is connected to both third radio 440 andfourth radio 458. Fourth radio 458 is connected to ATC4 461. ATC4 461 isconnected to fourth band pass filter 464. Fourth band pass filter 464 isconnected to MCU4 467. RFTL2 452, as well as Antenna A2 370, areconnected to MCU4 467.

In the exemplary embodiment of FIG. 4, first radio 405, second radio423, third radio 440, and fourth radio 458 typically are 30 Watt radios.Alternatively, these four radios can be of any wattage and generatesignals of any frequency. In alternate embodiments of the presentinvention, these four radios can be any type of radio frequency orsignal source. In a typical Ericsson RBS884 system, these four radiosare 30 Watt radios. Moreover, these four radios, depending on thewireless communications system, may transmit, for example, in the 850MHz bandwidth or the 1900 MHz bandwidth.

The Auto Tune Combiners, ATC1 408, ATC2 426, ATC3 443, and ATC4 461, asis known in the art, function to combine the signals from their attachedradios to provide an optimal output power for transmission on therespective antennas. These Auto Tune Combiners provide automaticcombining of a set number of transmit channels. Further, these Auto TuneCombiners typically monitor the change in operating frequency and powerof their corresponding transmitters and automatically tune each channelto the correct operating frequency. In one embodiment of the presentinvention, the Auto Tune Combiners, as well as the other components inthe system depicted in FIG. 4, may be obtained from Ericsson (such as inthe Ericsson RBS884 system).

The four band pass filters, 411, 429, 446, and 464, each serve to filterthe output of the Auto Tune Combiners to which they are connected. Inthis manner, the four band pass filters, as is known in the art, filterthe output of their respective Auto Tune Combiners so that the signaltransmitted on their respective antennas does not fall outside thebandwidth allocated to the wireless provider. For example, a wirelessprovider, in an e-band system, may be provided 5 MHz of bandwidth inwhich to transmit. The four band pass filters, in this example, wouldthen filter the output of their respective Auto Tune Combiners so as toensure that the transmitted signal falls within the allocated 5 MHzbandwidth. In this manner, the four band pass filters would eachfunction to filter out any signals that fall outside of the specified 5MHz bandwidth. The operation of band pass filters is known to thoseskilled in the art, and band pass filters are easily obtainable from anynumber of manufacturers, including Ericsson.

Consistent with the principles of the embodiments depicted in Figure 4,the multi-coupler units, MCUL 414, MCU2 432, MCU3 449, and MCU4 467,each serve as a connection point for their respective antennas. Inaddition, these four multi-coupler units each have test ports from whicha radio frequency test loop device can sample a forward signal and areflected signal. In this manner, the multicoupler units are passivedevices that serve simply to interconnect other devices of the systemdepicted in FIG. 4.

The antennas of the embodiment in FIG. 4, Antenna A1 365, Antenna A2370, Antenna B1 375, and Antenna B2 380, are typically unidirectionalantennas, but may be antennas of any type. In the embodiments of FIG. 3Aand FIG. 4, the four antennas depicted are directional antennas whicheach transmit in their respective sectors. For example, Antenna A1 365and Antenna A2 370 transmit in Sector A 355. In this case, these twoantennas are unidirectional antennas that transmit in a 180 degree area.Likewise, Antennas B1 375 and B2 380 transmit in Sector B 360 and, inthis case, are unidirectional antennas that transmit in a 180 degreearea. While unidirectional antennas are depicted in this embodiment ofthe present invention, other embodiments of the present invention mayemploy any type of antenna. For example, a wireless communicationssystem may be divided into any number of sectors, each with associatedantennas. In the case of a multi-sectored communications system, theantennas in a particular sector are typically configured to transmitonly in that sector. Alternatively, an omni-directional antenna may beused which transmits over the entire 360 degree area. The operation ofthese antennas is known to those skilled in the art, and these antennascan be obtained from any number of wireless equipment providers, such asEricsson.

RFTL1 417 and RFTL2 452, in this case, are radio frequency test loopdevices. As is commonly known, these radio frequency test loop devicestypically verify radio power. These devices each measure the forward andreflected signals and perform tests to verify the power of eachtransmitting radio. These radio frequency test loop devices then sendfeedback signals to their respective radios. In addition, these radiofrequency test loop devices typically verify the antennas by performinga voltage standing wave ratio (VSWR) measurement. RFTL1 417 and RFTL2452 each have two sets of forward and reflected test points. In thismanner, these devices may sample a forward signal and a reflected signalfrom two different transmit antennas as depicted in FIG. 4. In otherembodiments of the present invention, various radio frequency test loopdevices, such as RFTL1 417 and RFTL2 452, may contain any number of testpoints. RFTL1 417 and RFTL2 452 may be obtained from any number ofwireless equipment providers, such as Ericsson.

First multi-coupler 420 and second multi-coupler 455, as is commonlyknown, serve to interconnect RFTL1 417 and RFTL2 452 with the radiosthat they control. In the embodiment of FIG. 4, first multi-coupler 420allows the feedback signals produced by RFTL1 417 to pass to theirrespective radios. These feedback signals are depicted with dashedlines. In this case, RFTL1 417 generates two feedback signals denoted bypath A and path B. Likewise, RFTL2 452 generates two feedback signalsdenoted by the dashed lines. Second multi-coupler 455 allows these twofeedback signals, denoted C and D, to pass to their respective radios.

The operation of the system of FIG. 4 is described with respect to thefirst radio. The other radios operate in the same fashion. First radio405 generates a signal at a specific frequency or on a specific channel.The signal generated by first radio 405 is then processed by ATC1 408.This processing may include, for example, combining the signal generatedby first radio 405 with signals from other radios (not shown). Theoutput of ATC1 408 is then filtered by band pass filter 411. In thismanner, band pass filter 411 ensures that the signal ultimatelytransmitted on Antenna A1 365 remains within the allocated frequencyspectrum that is assigned to a particular wireless subscriber. The bandpass filter 411, therefore, ensures that no interference takes place.The output of band pass filter 411, which is the filtered and processedsignal generated by first radio 405 is then passed through MCU1 414 fortransmission on Antenna Al 365. While the signal is being transmitted onAntenna A1 365, RFTL1 417 samples the forward and reflected signals.RFTL1 417 performs various tests on the sampled forward and reflectedsignals and produces a feedback signal. The feedback signal associatedwith the first radio 405 is depicted by the dashed line labeled A. Thisfeedback signal generated by RFTL1 417 then passes through the firstmulti-coupler 420 and back to first radio 405. In this manner, thefeedback signal produced by RFTL1 417 serves to control the first radio405. RFTL1 417 performs various tests that ensure that first radio 405,as well as Antenna A1 365, are operating properly. In one embodiment ofthe present invention, RFTL1 417 may produce a feedback signal denotedby the dashed line labeled A that controls the power of first radio 405.In this example, RFTL1 417 may monitor the forward and reflectedsignals, perform tests on those signals, and output a feedback signalthat controls the power of first radio 405.

The remaining radios, second radio 423, third radio 440, and fourthradio 458 operate in a similar manner. The output of those respectiveradios, which is a signal generated at a specific frequency or on aspecific channel, is processed by their respective Auto Tune Combiners.The output of these Auto Tune Combiners is then filtered with theconnected band pass filter and transmitted on their respective antennasafter passing though their respective multi-coupler units.

RFTL1 417 and RFTL2 452 each sample two different forward and reflectedsignals from two different transmit paths. RFTL1 417 samples a forwardand reflected signal from the transmit path associated with Antenna A1365, as well as a forward and reflected signal associated with thetransmit path of Antenna B2 380. Likewise, RFTL2 452 samples a forwardand reflected signal from the transmit path associated with Antenna B1375, as well as a forward and reflected signal from the transmit pathassociated with Antenna A2 370. In this embodiment, RFTL1 417 samples aforward and reflected signal from antennas on two different sectors.Likewise, RFTL2 452 also samples a forward and reflected signal fromantennas on two different sectors. In this manner, RFTL1 417 and RFTL2452, after testing their sampled signals, send feedback signals toradios that are associated with two different sectors.

The configuration of the components in the exemplary embodiment of FIG.4 allows a wireless communications system to overcome the limitationsnoted in the background section. As previously described, the Auto TuneCombiners of the Ericsson RBS884 system have an 11-channel separationlimitation. In addition, the radio frequency transmit loop devices alsohave a 4-channel separation limitation. The configuration of FIG. 4,however, allows transmission on adjacent channels in the same sector. Inthe simple two-sector example of FIG. 4, first radio 405 transmits onAntenna A1 365 and fourth radio 458 transmits on Antenna A2 370. Thesetwo radios that transmit in the same sector on different antennas areassociated with different Auto Tune Combiners and different RFTLdevices. In this manner, the signals generated by first radio 405 andfourth radio 458 do no have to respect any of the limitations associatedwith the channel separation for Auto Tune Combiners and radio frequencytest loop devices. The signal path traced by first radio 405 iscompletely independent of the signal path traced by fourth radio 458.Since the signals generated by first radio 405 and fourth radio 458 donot pass through the same or sequentially connected Auto Tune Combinersor the same RTFL device, these two signals can reside on adjacentchannels. Therefore, a tighter use of spectrum can be achieved in SectorA.

Likewise, in Sector B, two different radios, second radio 423 and thirdradio 440, are associated with two different Auto Tune Combiners, ATC2426 and ATC3 443, as well as two different radio frequency test loopdevices, RFTL1 417 and RFTL2 452. In this manner, the signals producedby second radio 423 and third radio 440 do not pass through the same orsequentially connected Auto Tune Combiners or the same RFTL device.Therefore, the channels on which second radio 423 and third radio 440operate may be adjacent, thereby allowing a tighter use of channels in agiven spectrum.

Since the signals generated by first radio 405 and second radio 423share the same RFTL device, RFTL1 417, these two signals must beseparated by at least four channels. However, the signal generated byfirst radio 405 is transmitted on Antenna A1 365 associated with SectorA 355, while the signal generated by second radio 423 is transmitted onAntenna B2 380 associated with Sector B 360. While the signals generatedby first radio 405 and second radio 423 must be separated by fourchannels (because of the inherent limitation in RFTL1 417), these twosignals are transmitted on two different sectors. In this manner, firstradio 405 and second radio 423 may use different channel sets of FIG.2C. The channel sets of FIG. 2C have channels that are separated by fourchannels or 120 KHz. Therefore, the channel separation between Sector Aand Sector B in the case of first radio 405 and second radio 423 must be120 KHz or four channels.

Likewise, the channel separation between the signals generated by thirdradio 440 and fourth radio 458 must also be 120 KHz or four channels. Inthe embodiment of FIG. 4, the signal generated by third radio 440 andthe signal generated by fourth radio 458 each pass through the same RFTLdevice, RFTL2 452. As mentioned, RFTL2 452 has associated with it aninherent 4-channel separation limitation. Therefore, the channelsutilized by third radio 440 and fourth radio 458 must be separated by120 KHz or four channels. In this manner, third radio 440 and fourthradio 458 may use any one of the channel sets depicted in FIG. 2C. Forexample, third radio 440 may utilize channel 100, while fourth radio 458utilizes channel 104. This channel selection respects the 4-channelseparation limitation inherent in RFTL2 452.

In sum, by splitting the transmit paths, that is by splitting the AutoTune Combiners, and by sharing the RFTL devices between differentsectors, two radios associated with the same sector may operate onadjacent channels. The split path of the Auto Tune Combiners overcomesthe 11-channel separation limitation inherent in them. The shared RFTLdevices overcomes the 4-channel separation limitation for radios in thesame sector. Therefore, in the configuration of FIG. 4, first radio 405and second radio 423 may operate on a given single channel set of FIG.2C, while third radio 440 and fourth radio 458 operate on a seconddifferent channel set of FIG. 2C. In this manner, half of the 166allocated channel sets may be used in this simple two-sector wirelesscommunications system

FIG. 5 is a block diagram of a wireless communications system consistentwith the principles of the present invention. The exemplary embodimentof FIG. 5 extends the embodiment depicted in FIG. 4 to a 3-sectorcommunications system. A 3-sector communications system is depicted inFIG. 3B. In this typical configuration, the entire transmit area isdivided into three different sectors, Sector A 305, Sector B 320, andSector C 335. Each of these three different sectors comprises 120degrees of transmit area. A central tower 350 forms the mounting pointfor the antennas in each of the three different sectors. Sector A 305contains two antennas, Antenna A1 310 and Antenna A2 315. Sector B 320contains two antennas, Antenna B1 325 and Antenna B2 330. Likewise,Sector C 335 contains two antennas, Antenna C1 340 and Antenna C2 345.In other embodiments consistent with the principles of the presentinvention, the transmit area may be divided into any number of sectorsand each sector may have any number of antennas. For example, in the3-sector communications system depicted in FIG. 3B, each of the sectorsmay have additional antennas (not shown).

Since each of the sectors depicted in FIG. 3B operate in a 120 degreetransmit area, the antennas associated with that sector are typicallydirectional antennas. In this case, the antennas operating in Sector A305, for example, may be unidirectional antennas that broadcast insubstantially a 120 degree field. In other embodiments consistent withthe present invention, antennas associated with a particular sector maybe designed to transmit in the area associated with that sector. Aspreviously described, the antennas associated with each of the threesectors depicted in FIG. 3B, are commonly known and easily obtainablefrom any number of wireless equipment providers, such as Ericsson.

Referring now to FIG. 5, the components depicted are interconnected in amanner similar to that of FIG. 4. First radio 502 is connected to firstAuto Tune Combiner (ATC1) 504. ATC1 504 is connected to first band passfilter 506. First band pass filter 506 is connected to firstmulti-coupler unit (MCU1) 508. A first antenna (Antenna A1) 310 and afirst radio frequency test loop device (RFTL1) 510 are connected to MCU1508. RFTL1 510 is connected to first multicoupler 512. Firstmulti-coupler 512 is connected to first radio 502 and second radio 514.Second radio 514 is connected to second Auto Tune Combiner (ATC2) 516.ATC2 516 is connected to second band pass filter 518. Second band passfilter 518 is connected to second multi-coupler unit (MCU2) 520. Asecond antenna associated with Sector C (Antenna C2) 345, as well asRFTL1 510, are connected to MCU2 520.

The remaining two sets of components depicted in FIG. 5 are connected inthe same manner. Third radio 530 is connected to third Auto TuneCombiner (ATC3) 532 which is then connected to third band pass filter534 which is then connected to third multi-coupler unit (MCU3) 536. Afirst antenna associated with Sector B (Antenna B1) 325, as well as asecond radio frequency test loop device (RFTL2) 538, are connected toMCU3 536. RFTL2 538 is connected to second multi-coupler 540 which isthen connected to third radio 530 and fourth radio 542. Fourth radio 542is connected to fourth Auto Tune Combiner (ATC4) 544 which is thenconnected to fourth band pass filter 546. Fourth band pass filter 546 isconnected to fourth multi-coupler unit (MCU4) 548. A second antennaassociated with Sector A (Antenna A2) 315, as well as RFTL2 538, areconnected to MCU4 548.

In a similar fashion, fifth radio 560 is connected to fifth Auto TuneCombiner (ATC5) 562 which is then connected to fifth band pass filter564 which is then connected to fifth multi-coupler unit (MCU5) 566. Afirst antenna associated with Sector C (Antenna C1) 340 and a thirdradio frequency test loop device (RFTL3) 568 are connected to MCU5 566.A sixth radio 572 is connected to a sixth Auto Tune Combiner (ATC6) 574which is then connected to a sixth band pass filter 576 which is thenconnected to a sixth multi-coupler unit (MCU6) 578. A second antennaassociated with Sector B (Antenna B2) 330, as well as RFTL3 568, areconnected to MCU6 578. RFTL3 568 is connected to third multi-coupler570. Third multi-coupler 570 is connected to fifth radio 560 and sixthradio 572.

The components of the exemplary embodiment depicted in FIG. 5 possessthe same qualities and characteristics of the components described inreference to FIG. 4. For example, first radio 502 of FIG. 5 and firstradio 405 of FIG. 4 may be 30 Watt radios. Likewise, the Auto TuneCombiners of FIGS. 4 and 5 operate in a similar manner and possesssimilar characteristics. In addition, the band pass filters,multi-coupler units, radio frequency test loop devices, multicouplers,and antennas depicted in FIG. 5 possess the same qualities andcharacteristics of the like devices depicted in FIG. 4.

In another aspect consistent with the principles of the presentinvention, each of the first through sixth radios, 502, 514, 530, 542,560, and 572, may comprise multiple radio sources. For example, firstradio 502 may contain, for example, seven different radios sources.Therefore, the depiction of first radio 502 in FIG. 5 is consistent withseven radios. In this manner, Antenna Al 310 may have seven radiosassociated with it. Likewise, ATC1 504 may contain seven Auto TuneCombiners, one each for the seven radios comprising first radio 502. Anynumber of radios and associated Auto Tune Combiners may beinterconnected for transmission on any single antenna in a specificsector. The principles of the present invention are equally applicableto numerous radio configurations and not just the single radio perantenna configuration depicted in FIG. 4 and FIG. 5.

The operation of the components depicted in FIG. 5 is also similar tothe operation of the components previously described with respect toFIG. 4. For example, first radio 502 produces a radio signal at aspecific frequency or on a specific channel. That signal is thenprocessed by ATC1 504. The output of ATC1 504, which is the processedsignal generated by first radio 502, is then filtered by first band passfilter 506. This filtered signal is then passed through MCU1 508 fortransmission on Antenna A1 310. RFTL1 510 via a forward signal port anda reflected signal port contained in MCU1 508 samples the forward signaland reflected signal. RFTL1 510, as previously described, performsvarious tests on the forward signal and reflected signal and sends afeedback signal, denoted by the dashed line, through first multi-coupler512 and to first radio 502. RFTL1 510 through ports on MCU2 520 samplesthe forward signal and reflected signal of the transmit path associatedwith Antenna C2 345. In this manner, RFTL1 510 samples two sets offorward and reflected signals from two different antennas operating intwo different sectors. RFTL1 510, after performing tests on thesesignals, sends two different feedback signals through firstmulti-coupler 512 to first radio 502 and second radio 514. Thesefeedback signals are depicted by dashed lines labeled with the letters Aand B, with the feedback signal labeled A passing from RFTL1 510 tofirst radio 502 and the feedback signal labeled B passing from RFTL1 510to second radio 514.

The two other sets of radios depicted in FIG. 5 operate in the samefashion as the first set just described. Each of these two other sets ofcomponents have two different transmit paths. The second set ofcomponents depicted in the middle of FIG. 5 has two different transmitpaths, one associated with Antenna B1 325 and another associated withAntenna A2 315. In this manner, RFTL2 538 samples a forward single and areflected signal from each of the two transmit paths associated withAntenna B1 325 and Antenna A2 315. These two transmit paths also operateon two different sectors. In this manner, RFTL2 538 samples forward andreflected signals from antennas operating on two different sectors.

Likewise, RFTL3 568 samples a forward and reflected signal from atransmit path associated with Antenna C1 340, as well as a forward andreflected signal from a transmit path associated with Antenna B2 330.Just as in the previous two sets of components, RFTL3 568 samples aforward and reflected signal from two different transmit pathsassociated with two different sectors. In this case, RFTL3 568 samples aforward and reflected path from antennas associated with Sectors B andC.

Just as in the system described in FIG. 4, the system depicted in FIG. 5possesses a configuration of RFTL devices that sample forward andreflected signals from transmission paths of different sectors. Thedescription of the operation of the components of FIG. 4, as well astheir interaction in the system depicted in FIG. 4, is analogous to thecomponents and system depicted in FIG. 5.

The system depicted in FIG. 5 overcomes the same 11-channel separationlimitation and 4-channel separation limitation inherent in the Auto TuneCombiner and radio frequency transmit loop device, respectively. Just asin FIG. 4, the Auto Tune Combiners depicted in FIG. 5 carry with them an11-channel separation limitation. In a similar manner, the radiofrequency test loop devices depicted in FIG. 5 possess a 4-channelseparation limitation. By sharing an RFTL device between differenttransmit paths on different sectors, the 4-channel limitation isovercome for a given sector. Additionally, the shared RFTL deviceconfiguration of FIGS. 4 and 5 reduce the number of components that arenecessary to operate a wireless transmission site. As is plainly seen inFIG. 5, only three RFTL devices are necessary for a given six set ofradios transmitting in three different sectors on six differentantennas. Instead of having a separate RFTL device associated with eachantenna, the shared configuration of FIG. 5 allows for an RFTL device tomonitor two different transmit paths.

As seen in the example of FIG. 5, first radio 502 is the originationpoint for the transmit path associated with Antenna A1 310. Fourth radio542 is the origination point for the transmit path associated withAntenna A2 315. As discussed, Antenna A1 310 and Antenna A2 315 bothtransmit in Sector A 305. By splitting the transmit path between twodifferent sets of devices, the 11-channel limitation associated with theAuto Tune Combiner and the 4-channel limitation associated with the RFTLdevice is overcome. In this case, a signal generated by first radio 502,after processing and filtering, is transmitted on Antenna A1 310 inSector A 305. Likewise, a signal generated by a fourth radio 542, afterprocessing and filtering, is transmitted on Antenna A2 315 in Sector A305. Since the signal generated by first radio 502 and the signalgenerated by fourth radio 542 do not pass through any of the samecomponents, and more specifically, the same or sequentially connectedAuto Tune Combiners and the same RFTL device, these two signals canreside on adjacent channels. Therefore, a tighter use of an allottedspectrum can be maintained in Sector A.

Likewise, the same result is achieved in Sectors B and C, 320 and 335.In Sector B, a signal generated by third radio 530, after beingprocessed and filtered, is transmitted on Antenna B1 325 in Sector B320. A signal generated by a sixth radio 572, after being processed andfiltered, is transmitted on Antenna B2 330 in Sector B 320. Since thesignals generated by the third radio 530 and the sixth radio 572 do notshare any of the same components, and more specifically, the same orsequentially connected Auto Tune Combiners and the same radio frequencytest loop device, these two signals can reside on adjacent channels. Thesame is true for Sector C. A signal generated by second radio 514 andlater transmitted on Antenna C2 345, as well as a signal generated byfifth radio 560 and later transmitted on Antenna C1 340, may reside onadjacent channels because these two signals do not pass through the sameor sequentially connected Auto Tune Combiners or the same RFTL device.

As described in reference to FIG. 4, first radio 502 and second radio514 of FIG. 5, since they share the same RFTL device, RFTL1 510, mustrespect the 4-channel separation limitation inherent in that RFTLdevice. As mentioned, signals that pass through a single RFTL devicemust be separated by four channels or, in this case, 120 KHz. Withreference to FIG. 2C, this means that first radio 502 and second radio514 must use channels of any one of the channel sets depicted in FIG.2C. For example, if first radio 502 and second radio 514 choose to usechannel set three, then first radio 502 may broadcast on channel 111,while second radio 514 may broadcast on channel 115. In this manner, thesignals generated by first radio 502 and second radio 514 maintain the4-channel separation limitation required by RFTL 1 510. However, sincethe signal generated by first radio 502 is eventually transmitted inSector A 305 on Antenna A1 310 and the signal generated by second radio514 is eventually transmitted in Sector C 335 on Antenna C2 345, this4-channel separation limitation is imposed between different sectors andnot in the same sector.

In sum, because of the shared RFTL device configuration, the signalstransmitted on Antenna A1 310 and Antenna C2 345 must be four channelsapart. Likewise, the signals transmitted on Antenna B1 325 and AntennaA2 315, as well as the signals transmitted on Antenna C1 340 and AntennaB2 330, must also be four channels apart. With reference to FIG. 2C, 75%of the channels depicted in FIG. 2C may be used simultaneously with theimplementation of the wireless communications system depicted in FIG. 5.For example, first radio 502 and second radio 514 may choose a singlechannel set depicted in FIG. 2C (since these channel sets are fourchannels apart, therefore, respecting the 4-channel separationlimitation inherent in the RFTL device). Likewise, third radio 530 andfourth radio 542 may choose another different channel set from FIG. 2Cand fifth radio 560 and sixth radio 572 may choose a third differentchannel set from FIG. 2C. In this manner, for example, first radio 502and second radio 514 may choose to transmit on channel set three, thirdradio 530 and fourth radio 542 may choose to transmit on channel settwo, and fifth radio 560 and sixth radio 572 may choose to transmit onchannel set one. In this configuration, the number of channels that maybe used in a given spectrum is greatly increased.

If the transmission area were divided into four sectors, each with twodifferent antennas, then every single channel depicted in the fourchannel sets of FIG. 2C would be available for use. In thisconfiguration (not shown), the four different sets of radios (not shown)associated with the four different sectors could each utilize one of thefour different channel sets depicted in FIG. 2C. In this manner, theprinciples of the present invention can be extended to a communicationssystem with any number of different sectors.

In a further embodiment consistent with the principles of the presentinvention, the block diagram of FIG. 5 may represent multiple radios.For example, first radio 502 may comprise seven different radio sources.In this manner, first radio 502, comprised of seven different radios,transmit their seven different signals on Antenna A1 310. The sameconfiguration may be implemented in the second through sixth radios,514, 530, 542, 560, and 572. In this manner, each of the sets of radiosmay contain seven different radio sources for a total of 42 radios. Forexample, seven radios may generate signals that are later transmitted onAntenna A1 310 and a separate set of seven radios may generate signalsthat are transmitted on Antenna A2 315. In this configuration, 14 radiosbroadcast on two different antennas associated with a single sector.

In this case, the seven radios associated with Antenna A1 310 each passthrough the same set of Auto Tune Combiners 504. In this manner, theseven different signals produced by the seven different radios (depictedby first radio 502) are processed and combined by first Auto TuneCombiner (or first set of Auto Tune Combiners) 504. The resulting signalwhich is output from ATC1 504 is then filtered by first band pass filter506 and transmitted on Antenna A1 310. Since seven different radios(depicted by first radio 502) are processed by seven interconnected AutoTune Combiners (depicted by ATC1 504), these seven signals must respectthe 11-channel separation limitation inherent in Auto Tune Combiners. Inthis case, the set of radios whose signals are transmitted on Antenna A1310 must be separated by eleven channels or 330 KHz. With reference toFIG. 2B, this means that the set of radios whose signals are transmittedon Antenna A1 310 may operate on any one of the eleven channel setsdepicted in FIG. 2B. Likewise, the set of radios whose signals aretransmitted on Antenna C2 345 may operate on a set of channels depictedin FIG. 2B. Since the first set of radios and the second set of radiosshare the same RFTL device, RFTL1 510, the sets of channels that thesetwo different sets of radios select must be separated by four channels.For example, the first set of radios whose signal is transmitted onAntenna A1 310 may select channel set one of FIG. 2B. The second set ofradios whose signal is transmitted on Antenna C2 345 may select channelset four of FIG. 2B. In this manner, the channels that are broadcast onthese two antennas are separated by eleven channels within the set andfour channels between the sets.

This configuration, even with multiple sets of radios broadcasting on asingle antenna associated with a single sector, allows for increased useof the number of channels in a fixed spectrum. For example, the firstset of radios, whose signal is transmitted on Antenna A1 310, may usechannel set number one, while the second set of radios, whose signal istransmitted on Antenna C2 345, may use channel set four. In a similarmanner, a third set of radios, whose signals are transmitted on AntennaB1 325, may select channel set two, while a fourth set of radios, whosesignals are transmitted on Antenna A2 315, may select channel set fiveof FIG. B2. A fifth set of radios, whose signals are transmitted onAntenna C1 340, may select channel set three, and a sixth set of radios,whose signals are transmitted on Antenna B2 330, may select channel setsix. In this manner, for the three sector communications system depictedin FIG. 3B, six of the eleven channel sets depicted in FIG. 2B may beutilized simultaneously, thus increasing the amount of spectrum use in agiven sector.

The principles of the present invention depicted in FIGS. 4 and 5 may beextended to a five-sector communications system. In a five-sectorcommunications system (not shown), with two antennas per sector, most ofthe channel sets depicted in FIG. 2B can be utilized. For example, in afive-sector communications system, with two antennas per sector andmultiple radios per antenna, ten of the eleven channel sets depicted inFIG. 2B can be utilized simultaneously. In fact, the principles of thepresent invention can be used in any type of multi-sector wirelesscommunications system with the result of improved spectrum use.

FIG. 6 is a flow chart depicting an exemplary operation of the presentinvention. The two different flow charts depicted in FIG. 6 proceed inparallel. In this manner, the processes of each of these two flow chartsare performed simultaneously.

In step 605, a first set of radios generates a first set of signals. Instep 615, a first set of Auto Tune Combiners combines the first set ofsignals. Flow then proceeds to step 625 in which the combined first setof signals is filtered by a band pass filter. In step 635, the combinedfirst set of signals is sent to a multicoupler unit for transmission ona first antenna in a first sector. In step 645, an RFTL card samples thecombined first set of signals. This RFTL card, as previously described,performs tests on this first set of sampled signals. One of these tests,for example, may be a test to determine whether one of the first set ofradios needs its power adjusted. This test is depicted in step 655 inwhich the RFTL card determines whether the power of one of the first setof radios needs adjusting. If the power does not need adjusting, thenflow proceeds to step 645, in which the RFTL card continues to samplethe combined first set of signals. If the power does need adjusting,then flow proceeds to step 665, in which the power of one of the radiosof the first set of radios is adjusted.

In a similar parallel flow, a second set of radios generates a secondset of signals in step 610. In step 620, a second set of Auto TuneCombiners combines the second set of signals. Flow then proceeds to step630, in which the combined second set of signals is filtered by a bandpass filter. In step 640, the combined second set of signals is sent toa multi-coupler unit for transmission on a second antenna in a secondsector. Flow then proceeds to step 650, in which an RFTL card samplesthe combined second set of signals. As previously described, the RFTLcard samples a forward and reflected signal from a given transmit pathassociated with a given antenna. The RFTL card, as previously described,performs various tests on these signals to determine if the wirelesscommunications system is operating at a proper power. For example, theRFTL card may perform a test in which it determines whether one of theradios in the second set of radios is operating properly. This exemplarytest is depicted in step 660. In step 660, the RFTL card determineswhether one of the radios in the second set of radios needs its poweradjusted. If the radio does not need its power adjusted, then flowproceeds to step 650, in which the RFTL card samples the combined secondset of signals. If one of the radios in the second set of radios needsits power adjusted, then flow proceeds to step 670 in which the power ofthe radio is adjusted. From that point, flow returns to step 610, inwhich the second set of radios generates a second set of signals.

As previously described, the parallel flow of FIG. 6, and morespecifically, steps 645 and 650, occur with one radio frequency testloop device. In this case, the RFTL card mentioned in step 645 and step650 are the same RFTL device. In this manner, the RFTL card of step 645and step 650 samples both the first set of radio signals and the secondset of radio signals.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1. A method for improving the use of a transmission spectrum in amulti-sector wireless communications system, the method comprising:generating a first signal; processing the first signal with a first autotune combiner; transmitting the first signal on an antenna associatedwith a first sector; sampling the first signal with a radio frequencytest device; generating a fourth signal; processing the fourth signalwith a second auto tune combiner; transmitting the fourth signal on anantenna associated with the first sector; and sampling the fourth signalwith the radio frequency test device.
 2. The method of claim 1 furthercomprising: generating a second signal; generating a third signal;combining the first signal with the third signal before transmission;and combining the second signal with the fourth signal beforetransmission.
 3. The method of claim 2 wherein the first signal andfourth signal are transmitted on a first set of adjacent channels andthe second signal and third signal are transmitted on a second set ofadjacent channels.
 4. The method claim 1 further comprising: filteringan output of the first auto tune combiner before transmission; andfiltering an output of the second auto tune combiner beforetransmission.
 5. The method of claim 1 further comprising: adjusting afirst signal source power based on the sampled first signal; andadjusting a fourth signal source power based on the sampled fourthsignal.
 6. The method of claim 1 wherein the first signal and the fourthsignal are transmitted on adjacent channels.
 7. An apparatus forimproving the use of a transmission spectrum in a wirelesscommunications system, the apparatus comprising: a first radio sourcefor generating a first signal associated with a first sector; a firstauto tune combiner for processing the first signal; a first antennaassociated with the first sector for transmitting the first signal afourth radio source for generating a fourth signal associated with thefirst sector; and a second auto tune combiner for processing the fourthsignal; a second antenna associated with the first sector fortransmitting the fourth signal; a radio frequency test device forsampling the first and fourth signals.
 8. The apparatus of claim 7further comprising: a second radio source for generating a secondsignal; and a third radio source for generating a third signal; whereinthe first signal is combined with the third signal by a first auto tunecombiner before transmission and the second signal is combined with thefourth signal by a second auto tune combiner before transmission.
 9. Theapparatus of claim 8 wherein the first signal and fourth signal aretransmitted on a first set of adjacent channels and the second signaland third signal are transmitted on a second set of adjacent channels.10. The apparatus of claim 7 further comprising: a first band passfilter for filtering an output of the first auto tune combiner beforetransmission; and a second bandpass filter for filtering an output ofthe second auto tune combiner before transmission.
 11. The apparatus ofclaim 7 wherein the first signal and fourth signal are transmitted onadjacent channels.